Hanger expansion hook



FIG. 1 is a front view of the claimed design of a hanger expansion hook;

FIG. 2 is a side view thereof, the opposite side being a mirror image;

FIG. 3 is a back view thereof; and,

FIG. 4 is a front view thereof.

The broken lines showing environmental structures in FIG. 4 are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a hanger expansion hook, as shown and described. 